The invention relates to liquid pumping systems and particularly to verifying leak situations in such systems.
A check valve, also called a non-return valve, is very often used in connection with water pumps. Here, a check valves refers to a valve allowing flow in only one direction. Such check valves include, for instance, a non-return poppet valve and a non-return flap valve.
Solids carried by the water to be pumped may, however, cause a leak situation in such check valves. Impurities may be gathered for example in a system where the impurities of the water are gathered upon the non-return valves of a manifold when the valves are in a state preventing the flow. When liquid is transferred with a pump through such a non-return valve having been closed for long, the solids fall to the non-return valve mechanism immediately after the opening, possibly preventing the closing of the valve when the pumping has ended.
Verifying leaks caused by such check valves has proven difficult.